Blackyoshi04950 (Better known as black yoshi in most videos) is one of Mariotube Yoshichannel's other yoshi plushes that starred in Mario Gets Held Back And Gets Grounded and several other videos, including Teddy Bear Eats Blackyoshi04950. Blackyoshi04950 is one of the three yoshis with YouTube accounts, the other two are Baby Yoshi Yoshi & Yellow Yoshi Yoshi. Black yoshi joined YouTube the week after Baby yoshi yoshi and he even had the Mariotube Yoshichannel crew as his profile picture before the crew even started on December 4th, 2013. His youtube channel is here. His channel features several clips that were from baby yoshi yoshi's channel. He also played as Mario's brother in Mario gets held back and gets grounded. He loves Mario, although he thinks Mario is annoying.
Technically he was the first Mariotube Yoshichannel character considering Mariotube Yoshichannel used his avatar as the profile picture before he even uploaded his 1st video.
Mariotube Yoshichannel has stated that he likes Black Yoshi the most out of all of them. He has also stated that Black Yoshi once had a more expansive storyline.